decided i hated it ... started over.
the core support mounts are now inverted, so they bolt to the bottom of the frame instead. i was trying to keep the core support sitting on them even with a loose bolt, but this is just going to be way cleaner. the core support is basically flat against the front of the frame, so the lower plate will weld to it.
the bumper is also a completely separate mount now and should provide a little more protection. still need to figure out a better diagonal support thought. that might need to wait until it's built since i don't have the C30 crossmember modeled.